Involvement of dual-strand of the miR-144 duplex and their targets in the pathogenesis of lung squamous cell carcinoma.

The prognosis of patients with advanced-stage lung squamous cell carcinoma (LUSQ) is poor, and effective treatment protocols are limited. Our continuous analyses of antitumor microRNAs (miRNAs) and their oncogenic targets have revealed novel oncogenic pathways in LUSQ. Analyses of our original miRNA expression signatures indicated that both strands of miR-144 (miR-144-5p, the passenger strand; miR-144-3p, the guide strand) showed decreased expression in cancer tissues. Additionally, low expression of miR-144-5p significantly predicted a poor prognosis in patients with LUSQ by The Cancer Genome Atlas database analyses (overall survival, P = 0.026; disease-free survival, P = 0.023). Functional assays revealed that ectopic expression of miR-144-5p and miR-144-3p significantly blocked the malignant abilities of LUSQ cells, eg, cancer cell proliferation, migration, and invasion. In LUSQ cells, 13 and 15 genes were identified as possible oncogenic targets that might be regulated by miR-144-5p and miR-144-3p, respectively. Among these targets, we identified 3 genes (SLC44A5, MARCKS, and NCS1) that might be regulated by both strands of miR-144. Interestingly, high expression of NCS1 predicted a significantly poorer prognosis in patients with LUSQ (overall survival, P = 0.013; disease-free survival, P = 0.048). By multivariate analysis, NCS1 expression was found to be an independent prognostic factor for patients with LUSQ patients. Overexpression of NCS1 was detected in LUSQ clinical specimens, and its aberrant expression enhanced malignant transformation of LUSQ cells. Our approach, involving identification of antitumor miRNAs and their targets, will contribute to improving our understanding of the molecular pathogenesis of LUSQ.

Involvement of Dual Strands of miR-143 (miR-143-5p and miR-143-3p) and Their Target Oncogenes in the Molecular Pathogenesis of Lung Adenocarcinoma.

Our analyses of tumor-suppressive microRNAs (miRNAs) and their target oncogenes have identified novel molecular networks in lung adenocarcinoma (LUAD). Moreover, our recent studies revealed that some passenger strands of miRNAs contribute to cancer cell malignant transformation. Downregulation of both strands of the miR-143 duplex was observed in LUAD clinical specimens. Ectopic expression of these miRNAs suppressed malignant phenotypes in cancer cells, suggesting that these miRNAs have tumor-suppressive activities in LUAD cells. Here, we evaluated miR-143-5p molecular networks in LUAD using genome-wide gene expression and miRNA database analyses. Twenty-two genes were identified as potential miR-143-5p-controlled genes in LUAD cells. Interestingly, the expression of 11 genes (MCM4, RAD51, FAM111B, CLGN, KRT80, GPC1, MTL5, NETO2, FANCA, MTFR1, and TTLL12) was a prognostic factor for the patients with LUAD. Furthermore, knockdown assays using siRNAs showed that downregulation of MCM4 suppressed cell growth, migration, and invasion in LUAD cells. Aberrant expression of MCM4 was confirmed in the clinical specimens of LUAD. Thus, we showed that miR-143-5p and its target genes were involved in the molecular pathogenesis of LUAD. Identification of tumor-suppressive miRNAs and their target oncogenes may be an effective strategy for elucidation of the molecular oncogenic networks of this disease.

Dual strands of the miR-145 duplex (miR-145-5p and miR-145-3p) regulate oncogenes in lung adenocarcinoma pathogenesis.

Our original microRNA (miRNA) expression signatures (based on RNA sequencing) revealed that both strands of the miR-145 duplex (miR-145-5p, the guide strand, and miR-145-3p, the passenger strand) were downregulated in several types of cancer tissues. Involvement of passenger strands of miRNAs in cancer pathogenesis is a new concept in miRNA biogenesis. In our continuing analysis of lung adenocarcinoma (LUAD) pathogenesis, we aimed here to identify important oncogenes that were controlled by miR-145-5p and miR-145-3p. Downregulation of miR-145-5p and miR-145-3p was confirmed in LUAD clinical specimens. Functional assays showed that miR-145-3p significantly blocked the malignant abilities in LUAD cells, e.g., cancer cell proliferation, migration and invasion. Thus, the data showed that expression of the passenger strand of the miR-145-duplex acted as an anti-tumor miRNA. In LUAD cells, we identified four possible target genes (LMNB2, NLN, SIX4, and DDC) that might be regulated by both strands of miR-145. Among the possible targets, high expression of LMNB2 predicted a significantly poorer prognosis of LUAD patients (disease-free survival, p = 0.0353 and overall survival, p = 0.0017). Overexpression of LMNB2 was detected in LUAD clinical specimens and its aberrant expression promoted malignant transformation of LUAD cells. Genes regulated by anti-tumor miR-145-5p and miR-145-3p are closely involved in the molecular pathogenesis of LUAD. We suggest that they are promising prognostic markers for this disease. Our approach, based on the roles of anti-tumor miRNAs, will contribute to improved understanding of the molecular pathogenesis of LUAD.

MicroRNAs in non-small cell lung cancer and idiopathic pulmonary fibrosis.

In spite of advances in the diagnosis and current molecular target therapies of lung cancer, this disease remains the most common cause of cancer-related death worldwide. Approximately 80% of lung cancers is non-small cell lung cancer (NSCLC), and 5-year survival rate of the disease is ~20%. On the other hand, idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of unknown etiology. IPF is refractory to treatment and has a very low survival rate. Moreover, IPF is frequently associated with lung cancer. However, the common mechanisms shared by these two diseases remain poorly understood. In the post-genome sequence era, the discovery of noncoding RNAs, particularly microRNAs (miRNAs), has had a major impact on most biomedical fields, and these small molecules have been shown to contribute to the pathogenesis of NSCLC and IPF. Investigation of novel RNA networks mediated by miRNAs has improved our understanding of the molecular mechanisms of these diseases. This review summarizes our current knowledge on aberrantly expressed miRNAs regulating NSCLC and IPF based on miRNA expression signatures.

The microRNA expression signature of small cell lung cancer: tumor suppressors of miR-27a-5p and miR-34b-3p and their targeted oncogenes.

Small cell lung cancer (SCLC) constitutes approximately 15% of all diagnosed lung cancers. SCLC is a particularly lethal malignancy, as the 2-year survival rate after appropriate treatment is less than 5%. The patients with SCLC have not been received a benefit of the recently developed molecular targeted treatment. Therefore, a new treatment strategy is necessary for the patients. The molecular mechanisms underlying the aggressiveness of SCLC cells and their development of treatment-resistance are still ambiguous. In this study, we newly constructed a microRNA (miRNA) expression signature of SCLC by analysis of autopsy specimens. Based on the resultant signature, four miRNAs (miR-27a-5p, miR-485-3p, miR-34-5p and miR-574-3p) were found to be candidate anti-tumor miRNAs. To investigate their functional importance, we first validated the downregulation of miR-27a-5p and miR-34b-3p in SCLC clinical specimens. Next, we demonstrated that ectopic expression of both miR-27a-5p and miR-34b-3p significantly inhibited cancer cell aggressiveness. Our in silico analyses showed that four genes (topoisomerase 2 alpha (TOP2A), maternal embryonic leucine zipper kinase (MELK), centromere protein F (CENPF) and SRY-box 1 (SOX1) were identified as miR-27a-5p- and miR-34b-3p-regulated genes. Based on immunohistochemical analysis, TOP2A, MELK and CENPF were involved in SCLC pathogenesis. These genes might contribute to high proliferation and early metastatic spread of SCLC cells. Elucidation of differentially expressed miRNA-mediated cancer pathways based on SCLC signature may provide new insights into the mechanisms of SCLC pathogenesis.

Napsin A levels in epithelial lining fluid as a diagnostic biomarker of primary lung adenocarcinoma.

BACKGROUND: It is crucial to develop novel diagnostic approaches for determining if peripheral lung nodules are malignant, as such nodules are frequently detected due to the increased use of chest computed tomography scans. To this end, we evaluated levels of napsin A in epithelial lining fluid (ELF), since napsin A has been reported to be an immunohistochemical biomarker for histological diagnosis of primary lung adenocarcinoma. METHODS: In consecutive patients with indeterminate peripheral lung nodules, ELF samples were obtained using a bronchoscopic microsampling (BMS) technique. The levels of napsin A and carcinoembryonic antigen (CEA) in ELF at the nodule site were compared with those at the contralateral site. A final diagnosis of primary lung adenocarcinoma was established by surgical resection. RESULTS: We performed BMS in 43 consecutive patients. Among patients with primary lung adenocarcinoma, the napsin A levels in ELF at the nodule site were markedly higher than those at the contralateral site, while there were no significant differences in CEA levels. Furthermore, in 18 patients who were undiagnosed by bronchoscopy and finally diagnosed by surgery, the napsin A levels in ELF at the nodule site were identically significantly higher than those at the contralateral site. In patients with non-adenocarcinoma, there were no differences in napsin A levels in ELF. The area under the receiver operator characteristic curve for identifying primary lung adenocarcinoma was 0.840 for napsin A and 0.542 for CEA. CONCLUSION: Evaluation of napsin A levels in ELF may be useful for distinguishing primary lung adenocarcinoma.

Regulation of LOXL2 and SERPINH1 by antitumor microRNA-29a in lung cancer with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that is refractory to treatment and carries a high mortality rate. IPF is frequently associated with lung cancer. Identification of molecular targets involved in both diseases may elucidate novel molecular mechanisms contributing to their pathology. Recent studies of microRNA (miRNA) expression signatures showed that microRNA-29a (miR-29a) was downregulated in IPF and lung cancer. The aim of this study was to investigate the functional significance of miR-29a in lung cancer cells (A549 and EBC-1) and lung fibroblasts (MRC-5) and to identify molecular targets modulated by miR-29a in these cells. We confirmed the downregulation of miR-29a in clinical specimens of IPF and lung cancer. Restoration of miR-29a suppressed cancer cell aggressiveness and fibroblast migration. A combination of gene expression data and in silico analysis showed that a total of 24 genes were putative targets of miR-29a. Among them, lysyl oxidase-like 2 (LOXL2) and serpin peptidase inhibitor clade H, member 1 (SERPINH1) were direct targets of miR-29a by luciferase reporter assays. The functions of LOXL2 and SERPINH1 contribute significantly to collagen biosynthesis. Overexpression of LOXL2 and SERPINH1 was observed in clinical specimens of lung cancer and fibrotic lesions. Downregulation of miR-29a caused overexpression of LOXL2 and SERPINH1 in lung cancer and IPF, suggesting that these genes are involved in the pathogenesis of these two diseases.

Serum B cell-activating factor (BAFF) level in connective tissue disease associated interstitial lung disease.

BACKGROUND: Interstitial lung diseases (ILDs) are common in patients with connective tissue diseases (CTDs). Although the diagnosis of an underlying CTD in ILD (CTD-ILD) affects both prognosis and treatment, it is sometimes difficult to distinguish CTD-ILD from chronic fibrosing interstitial pneumonia (CFIP). B cell-activating factor belonging to the tumour necrosis factor family (BAFF) plays a crucial role in B cell development, survival, and antibody production. METHODS: We examined serum levels of BAFF, surfactant protein D (SP-D), and Krebs von den Lungen-6 (KL-6) in 33 patients with CTD-ILD, 16 patients with undifferentiated CTD-ILD, 19 patients with CFIP, and 26 healthy volunteers. And we analysed the relationship between serum BAFF levels and pulmonary function, as well as the expression of BAFF in the lung tissue of patients with CTD-ILD. RESULTS: Serum levels of BAFF were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. However, there were no significant differences in serum levels of SP-D and KL-6. Furthermore, serum BAFF levels in CTD-ILD patients were inversely correlated with pulmonary function. BAFF was strongly expressed in the lungs of CTD-ILD patients, but weakly in normal lungs. DISCUSSION: This is the first study to demonstrate that serum BAFF levels were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. Furthermore, serum BAFF levels were correlated with pulmonary function. We consider that serum BAFF levels in patients with CTD-ILD reflect the presence of ILDs disease activity and severity. CONCLUSION: These finding suggest that BAFF may be a useful marker for distinguishing CTD-ILD from CFIP.

[A case of meningeal carcinomatosis of lung adenocarcinoma well controlled by re-treatment with gefitinib].

A 74-year-old-woman who had never smoked was diagnosed in 2004 with cT3N2M1, stage IV primary pulmonary adenocarcinoma. After seven courses of chemotherapy with carboplatin and paclitaxel, she was given gefitinib as second-line therapy and made satisfactory progress. However, gefitinib was discontinued after 3 years of treatment due to re-growth of the tumors. She was then given chemotherapy with docetaxel as a third-line therapy. Over the course of time, meningeal carcinomatosis occurred in conjunction with her previous disease. Upon re-treatment with gefitinib, her meningeal carcinomatosis showed some improvement despite the growing primary tumor, so her QOL was improved. She is now visiting a hospital as an outpatient. When analysis of the EGFR gene mutant was conducted, deletion mutation of E746-A750 in exon 19 was revealed in the 2004 pulmonary tissue, as well as the cytological examination of cerebrospinal fluid and pulmonary tissue after recurrence. No change has been observed. Once gefitinib proved effective, re-treatment with gefitinib was considered useful after its discontinuation.

Regulation of KIF2A by Antitumor miR-451a Inhibits Cancer Cell Aggressiveness Features in Lung Squamous Cell Carcinoma.

In the human genome, miR-451a is encoded close to the miR-144 on chromosome region 17q11.2. Our previous study showed that both strands of pre-miR-144 acted as antitumor miRNAs and were involved in lung squamous cell carcinoma (LUSQ) pathogenesis. Here, we aimed to investigate the functional significance of miR-451a and to identify its targeting of oncogenic genes in LUSQ cells. Downregulation of miR-451a was confirmed in LUSQ clinical specimens, and low expression of miR-451a was significantly associated with poor prognosis of LUSQ patients (overall survival: p = 0.035, disease-free survival: p = 0.029). Additionally, we showed that ectopic expression of miR-451a significantly blocked cancer cell aggressiveness. In total, 15 putative oncogenic genes were shown to be regulated by miR-451a in LUSQ cells. Among these targets, high kinesin family member 2A (KIF2A) expression was significantly associated with poor prognosis (overall survival: p = 0.043, disease-free survival: p = 0.028). Multivariate analysis showed that KIF2A expression was an independent prognostic factor in patients with LUSQ (hazard ratio = 1.493, p = 0.034). Aberrant KIF2A expression promoted the malignant transformation of this disease. Analytic strategies based on antitumor miRNAs and their target oncogenes are effective tools for identification of novel molecular pathogenesis of LUSQ.

Molecular Pathogenesis of Gene Regulation by the miR-150 Duplex: miR-150-3p Regulates TNS4 in Lung Adenocarcinoma.

Based on our miRNA expression signatures, we focused on miR-150-5p (the guide strand) and miR-150-3p (the passenger strand) to investigate their functional significance in lung adenocarcinoma (LUAD). Downregulation of miR-150 duplex was confirmed in LUAD clinical specimens. In vitro assays revealed that ectopic expression of miR-150-5p and miR-150-3p inhibited cancer cell malignancy. We performed genome-wide gene expression analyses and in silico database searches to identify their oncogenic targets in LUAD cells. A total of 41 and 26 genes were identified as miR-150-5p and miR-150-3p targets, respectively, and they were closely involved in LUAD pathogenesis. Among the targets, we investigated the oncogenic roles of tensin 4 (TNS4) because high expression of TNS4 was strongly related to poorer prognosis of LUAD patients (disease-free survival: p = 0.0213 and overall survival: p = 0.0003). Expression of TNS4 was directly regulated by miR-150-3p in LUAD cells. Aberrant expression of TNS4 was detected in LUAD clinical specimens and its aberrant expression increased the aggressiveness of LUAD cells. Furthermore, we identified genes downstream from TNS4 that were associated with critical regulators of genomic stability. Our approach (discovery of anti-tumor miRNAs and their target RNAs for LUAD) will contribute to the elucidation of molecular networks involved in the malignant transformation of LUAD.

Downregulation of matrix metalloproteinase 14 by the antitumor miRNA, miR-150-5p, inhibits the aggressiveness of lung squamous cell carcinoma cells.

In the present study, in order to elucidate the aggressive nature of lung squamous cell carcinoma (LUSQ), we investigated the oncogenic RNA networks regulated by antitumor microRNAs (miRNAs or miRs) in LUSQ cells. The analysis of our original miRNA expression signatures of human cancers revealed that microRNA­150­5p (miR­150­5p) was downregulated in various types of cancer, indicating that miR­150­5p acts as an antitumor miRNA by targeting several oncogenic genes. Thus, the aims of this study were to investigate the antitumor roles of miR­150­5p in LUSQ cells and to identify oncogenes regulated by miR­150­5p that are involved in the aggressive behavior of LUSQ. The downregulation of miR­150­5p was validated in clinical samples of LUSQ and cell lines (SK-MES­1 and EBC­1). The ectopic overexpression of miR­150­5p significantly suppressed cancer cell aggressiveness. Comprehensive gene expression analyses revealed that miR­150­5p regulated 9 genes in the LUSQ cells. Among these, matrix metalloproteinase 14 (MMP14) was found to be a direct target of miR­150­5p, as shown by luciferase reporter assay. The knockdown of MMP14 using siRNA against MMP14 (si-MMP14) significantly inhibited cancer cell migration and invasion. The overexpression of MMP14 was detected in clinical specimens of LUSQ by immunohistochemistry. On the whole, these findings suggest that the downregulation of miR­150­5p and the overexpression of MMP14 may be deeply involved in the pathogenesis of LUSQ.

[A possible case of drug-induced pneumonia due to L-carbocisteine].

A 70-year-old man presented with a deteriorating fever and productive cough after the administration of drugs including L-carbocisteine against the common cold. Since chest radiograph revealed pulmonary infiltrates in the right lower lung field, he was admitted to our hospital, then L-carbocisteine was continued and antibiotics started. However, his symptoms, laboratory findings, and hypoxia worsened. Pulmonary infiltrates on his chest radiograph increased and chest CT demonstrated pulmonary consolidation with traction bronchiectasis and ground glass opacity with thickened of interlobular septae in the right lung field. Analysis of bronchoalveolar lavage fluid showed elevated numbers of total cells, neutrophils and eosinophils, and the CD4/CD8 ratio was 5.65. Under a suspected diagnosis of drug-induced pneumonia, we halted L-carbocisteine administration stopped and began corticosteroid therapy. Subsequently his symptoms and findings markedly improved. The drug lymphocyte stimulation test for L-carbocisteine using peripheral blood lymphocytes showed positive results. On the basis of the clinical course, laboratory and radiographic findings, we considered this case to possibly be drug-induced pneumonia due to L-carbocisteine. To our knowledge, this is possibly the first case of L-carbocisteine-induced pneumonia to be reported.

[Bronchial asthma attack with lactic acidosis and hypokalemia in a case receiving high dose inhalation of procaterol hydrochloride].

We report a case of bronchial asthma attack with lactic acidosis and hypokalemia in a patient receiving high-dose inhalation of procaterol hydrochloride. A 28-year-old man was transferred to our hospital because of adynamia, nausea and dyspnea. He had used inhaled procaterol hydrochloride with a pressurized metered dose inhaler about 20 times before admission. On admission, there were no signs of shock state or hypoxemia and laboratory data showed hypokalemia, hyperglycemia and metabolic acidosis with elevated anion gap. Lactic acidosis was identified as the reason for the metabolic acidosis with elevated anion gap. Lactic acidosis improved after 12 hours. Lactic acidosis due to high dose inhalation of procaterol hydrochloride was suggested.

Regulation of TPD52 by antitumor microRNA-218 suppresses cancer cell migration and invasion in lung squamous cell carcinoma.

The development of targeted molecular therapies has greatly benefited patients with lung adenocarcinomas. In contrast, these treatments have had little benefit in the management of lung squamous cell carcinoma (lung SCC). Therefore, new treatment options based on current genomic approaches are needed for lung SCC. Aberrant microRNA (miRNA) expression has been shown to promote lung cancer development and aggressiveness. Downregulation of microRNA-218 (miR-218) was frequently observed in our miRNA expression signatures of cancers, and previous studies have shown an antitumor function of miR-218 in several types of cancers. However, the impact of miR-218 on lung SCC is still ambiguous. The present study investigated the antitumor roles of miR-218 in lung SCC to identify the target genes regulated by this miRNA. Ectopic expression of miR-218 greatly inhibited cancer cell migration and invasion in the lung SCC cell lines EBC-1 and SK-MES-1. Through a combination of in silico analysis and gene expression data searching, tumor protein D52 (TPD52) was selected as a putative target of miR-218 regulation. Moreover, direct binding of miR-218 to the 3'-UTR of TPD52 was observed by dual luciferase reporter assay. Overexpression of TPD52 was observed in lung SCC clinical specimens, and knockdown of TPD52 significantly suppressed cancer cell migration and invasion in lung SCC cell lines. Furthermore, the downstream pathways mediated by TPD52 involved critical regulators of genomic stability and mitotic checkpoint genes. Taken together, our data showed that downregulation of miR-218 enhances overexpression of TPD52 in lung SCC cells, promoting cancer cell aggressiveness. Identification of tumor-suppressive miRNA-mediated RNA networks of lung SCC will provide new insights into the potential mechanisms of the molecular pathogenesis of the disease.

Comparison of the COPD Population Screener and International Primary Care Airway Group questionnaires in a general Japanese population: the Hisayama study.

BACKGROUND: The incidence of chronic obstructive pulmonary disease (COPD) is increasing worldwide. In Japan and other countries, epidemiological studies have found that many patients with COPD are underdiagnosed and untreated, and thus, early detection and treatment of COPD has been emphasized. Screening questionnaires may have utility in the initial detection of COPD. OBJECTIVE: This study aimed to validate and compare the COPD Population Screener (COPD-PS) and the International Primary Care Airway Group (IPAG) questionnaires in a general Japanese population. PATIENTS AND METHODS: Eligible subjects 40 years of age and older living in the town of Hisayama were solicited to participate in a health checkup in 2012. All subjects 40-79 years of age without physician-diagnosed asthma or lung resection were recruited, and 2,336 subjects who fully completed both questionnaires and who had valid spirometry measurements were analyzed. Persistent airflow obstruction (AO) was defined by a postbronchodilator forced expiratory volume in 1 second/forced vital capacity <0.70. Receiver operating characteristic curves, net reclassification improvement, and integrated discrimination improvement were used to examine the ability of the COPD-PS and IPAG questionnaires to discriminate between subjects with and without AO. RESULTS: The overall area under the receiver operating characteristic curve for the COPD-PS questionnaire was 0.747 (95% confidence interval [CI], 0.707-0.788) and for the IPAG was 0.775 (95% CI, 0.735-0.816), with no significant difference (P=0.09). The net reclassification improvement and integrated discrimination improvement were -0.107 (95% CI, -0.273-0.058; P=0.203) and -0.014 (95% CI, -0.033-0.006; P=0.182), respectively. CONCLUSION: The five-item COPD-PS questionnaire was comparable to the eight-item IPAG for discriminating between subjects with and without AO. The COPD-PS is a simple and useful screening questionnaire for persistent AO.

Dual-strand tumor-suppressor microRNA-145 (miR-145-5p and miR-145-3p) coordinately targeted MTDH in lung squamous cell carcinoma.

Patients with lung adenocarcinoma may benefit from recently developed molecular targeted therapies. However, analogous advanced treatments are not available for patients with lung squamous cell carcinoma (lung SCC). The survival rate of patients with the advanced stage of lung SCC remains poor. Exploration of novel lung SCC oncogenic pathways might lead to new treatment protocols for the disease. Based on this concept, we have identified microRNA- (miRNA) mediated oncogenic pathways in lung SCC. It is well known that miR-145-5p (the guide strand) functions as a tumor suppressor in several types of cancer. However, the impact of miR-145-3p (the passenger strand) on cancer cells is still ambiguous. Expression levels of miR-145-5p and miR-145-3p were markedly reduced in cancer tissues, and ectopic expression of these miRNAs inhibited cancer cell aggressiveness, suggesting that both miR-145-3p as well as miR-145-5p acted as antitumor miRNAs. We identified seven putative target genes (MTDH, EPN3, TPD52, CYP27B1, LMAN1, STAT1 and TXNDC12) that were coordinately regulated by miR-145-5p and miR-145-3p in lung SCC. Among the seven genes, we found that metadherin (MTDH) was a direct target of these miRNAs. Kaplan-Meier survival curves showed that high expression of MTDH predicted reduced survival of lung SCC patients. We investigated pathways downstream from MTDH by using genome-wide gene expression analysis. Our data showed that several anti-apoptosis and pro-proliferation genes were involved in pathways downstream from MTDH in lung SCC. Taken together, both strands of miR-145, miR-145-5p and miR-145-3p are functional and play pivotal roles as antitumor miRNAs in lung SCC.